The invention pertains to bulk filling containers in general and more specifically, to a process for simultaneously drawing a liquid into a plurality of containers by surrounding the containers in a vacuum and introducing the liquid into a tray then reducing the vacuum or adding slowly pressure to allow the liquid to be drawn into the container.
Previously, many methods have been used to provide an effective means of filling containers with a liquid. In volume production it is common to utilize conveyers, where one or more tubes or hollow needles connected to a liquid-filled reservoir insert the liquid under pressure into the containers. The appropriate volume of liquid is usually controlled with valves or positive displacement pumps that modulate in sequence with the conveyer to insert just the correct amount at the proper time. While this process is effective, the speed is normally limited to some 100 to 1,000 units per minute.
A search of the prior art did not disclose any patents that possess the novelty of the instant invention, however the following U.S. patents are considered related:
Poynter, et al. in U.S. Pat. No. 6,089,676 teaches a process and apparatus for providing an air shower to a critical fill zone of a liquid filling operation for preventing entry of particulate, non-viable and viable particulate, into the critical filling zone by providing opposed flows of pressurized air in laminar flows.
U.S. Pat. No. 4,114,659 issued to Goldberg, et al. is for a pipette filling and liquid dispensing device that is attached to a pipette by a flexible conduit. A resilient, compressible bulb is connected to the conduit, in which a closable opening is provided. By means of the opening, an alternate connection may be established between the interior of the conduit and the opening by uncovering the opening. A valve unit is inserted into the conduit, and as it is releasably connected with the conduit, it is also easily removed.
In the past, when large quantities of items were to be bottled or filled into smaller containers, some type of automation was required which was expensive to procure and in most cases was dedicated to a single product line. This approach was reasonable and well-accepted in the art, however, there are some drawbacks when it comes to smaller containers, particularly if the neck is under 0.50 inches (1.27 cm) in diameter. There is a time consideration for filling these containers, as a normal nozzle or hollow needle is limited in its diameter, as it can be no larger than the opening itself. In small opening containers the problem is amplified, particularly if the liquid to be filled is viscous. While most aqueous solutions, such as solvents are easily filled, emulsions, creams, ointments, lotion, paste, jelly and syrup create troublesome problems relative to the pressures required to inject the liquid through the nozzles and also the obvious expended time factors. Therefore the primary object of the invention is to circumvent the use of nozzles or small orifices and to utilize a pressure difference to draw the liquid into the container. This approach is convenient and has many advantages for the smaller containers, as a large number of containers may be processed at the same time, limited only by the size of a vacuum chamber and the capacity of the vacuum pump.
An important object of the invention is that the equipment may be used for a wide variety of liquids and configurations of containers, as the containers only need to be placed in a tray upside down, thereby making the size and shape of both the containers and tray of little importance.
Another object of the invention is that the liquid may be inserted into a diversity of containers, such as glass bottles, glass vials, glass tubes, plastic bottles, plastic vials, aluminum, or other metal tubes, plastic tubes, pipettes etc. and even semi-rigid plastic bags.
Still another object of the invention is that the containers may be nested together in close proximity, thus permitting a large number of containers to be processed in a minimum of space. The handling is also simple, as filled containers may be removed by hand or machines and manually or mechanically turned to attach a lid or applicator to the top or an entire rack or tray may be turned over, thus exposing the tops ready for attachment of a lid or an applicator.
Yet another object of the invention is that the head space or amount of air between the liquid and the lid may be easily calculated and the negative pressure level of the vacuum chamber predetermined, which permits complete control of the level of all of the containers simultaneously.
Another object of the invention is that the filled volume can be precisely controlled in microliters.
These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.